Come to know Big and Little Dippers | Favorite Star Patterns | EarthSky Come to know Big and Little Dippers By Bruce McClure in Favorite Star Patterns | March 13, 2016 The Big Dipper is easy. And, once you find it, you can find the Little Dipper, too. Plus … learn how the stars of the Big Dipper are moving in space. View larger . | Big and Little Dippers at different seasons, and different times of night, as captured by Matthew Chin in Hong Kong. A fixture of the northern sky, the Big and Little Dippers swing around the north star Polaris like riders on a Ferris wheel. They go full circle around Polaris once a day – or once every 23 hours and 56 minutes. If you live at temperate latitudes in the Northern Hemisphere, simply look northward and chances are that you’ll see the Big Dipper in your nighttime sky. It looks just like its namesake. Once you’ve found the Big Dipper, it’s only a hop, skip and jump to Polaris and the Little Dipper. Follow the links below to learn more about the Big and Little Dippers.

How the Big Dipper’s star are moving in space. If you’re in the northern U.S., Canada or at a similar latitude, the Big Dipper is circumpolar for you – always above the horizon. These images show the Dipper’s location at around midnight in these seasons. Just remember “spring up and fall down” for the Dipper’s appearance in our northern sky. It ascends in the northeast on spring evenings, and descends in the northwest on fall evenings. Image via burro.astr.cwru.edu View larger. | The Big Dipper seen in the midst of the northern lights, taken in 2012 by EarthSky Facebook friend Birgit Boden in northern Sweden. View larger. | Here’s the Big Dipper in autumn, when it’s descending in the northwest in the evening, as seen by EarthSky Facebook friend John Michael Mizzi on the island of Gozo, south of Italy. Thank you, John Michael! How to find the Big Dipper. Depending upon the season of the year, the Big Dipper can be found high in the northern sky or low in the northern sky. Just remember the old saying spring up and fall down.

On spring and summer evenings, the Big Dipper shine highest in the sky. On autumn and winter evenings, the Big Dipper lurks closest to the horizon. Given an unobstructed horizon, latitudes at and north of Little Rock, Arkansas (35 degrees north) can expect to see the Big Dipper at any hour of the night for all days of the year. As for the Little Dipper, it is circumpolar – always above the horizon – as far south as the tropic of Cancer (23.5 degrees north latitude). Stars in the Big Dipper via EarthSky Facebook friend Ken Christison. He captured this photo on September 9, 2013. No matter what time of year you look, the two outer stars in the Big Dipper’s bowl always point to Polaris. How to use Big Dipper to find Little Dipper. Notice that the Big Dipper has two parts – a bowl and a handle. Notice the two outer stars in the bowl of the Big Dipper. They are called Dubhe and Merak, and an imaginary line drawn between them goes to Polaris, the North Star. That’s why Dubhe and Merak are known in skylore as The Pointers.

In turn, Polaris marks the end of the Little Dipper’s Handle. So why isn’t the Little Dipper as easy to pick out as the Big Dipper? The answer is that, like the Big Dipper, the Little Dipper has 7 stars. But the 4 stars in between Polaris and the outer bowl stars – Kochab and Pherkad – are rather dim. You need a dark country sky to see all 7. The Big Dipper is part of Ursa Major, the celestial Great Bear. Image via storybookipedia History and mythology of the celestial Bears. The Big Dipper is really an asterism – a star pattern that is NOT a constellation. The Big Dipper is a clipped version of the constellation Ursa Major the Big Bear, these Big Dipper stars outlining the Bear’s tail and hindquarters. In the star lore of the Micmacs in Canada, the Big Dipper is also associated with a bear but with a different twist. The Micmacs see the Big Dipper bowl as Celestial Bear, and the 3 stars of the handle as hunters chasing the Bear.

The starry sky serves as a calendar and a story book, as is beautifully illustrated by the Micmac tale of Celestial Bear. In autumn, the hunters finally catch up with the Bear, and it’s said that the blood from the Bear colors the autmn landscape. In another version of the story, Celestial bear hits its nose when coming down to Earth, with its bloody nose giving color to autumn leaves. When Celestial Bear is seen right on the northern horizon on late fall and early winter evenings, it’s a sure sign that the hibernation season is upon us. The Little Dipper is also an asterism, these stars belonging to the constellation Ursa Minor the Little Bear. In ancient times, the Little Dipper formed the wings of the constellation Draco the Dragon. But when the seafaring Phoenicians met with the Greek astronomer Thales around 600 B.C., they showed him how to use the Little Dipper stars to navigate. Thereby, Thales clipped Draco’s wings, to create a new constellation that gave Greek sailors a new way to steer by the stars.

In Thales’s day, the stars Kochab and Pherkad (rather than Polaris) marked the approximate direction of the north celestial pole – the point in the sky that is directly above the Earth’s North Pole. To this day, Kochab and Pherkad are still known as the Guardians of the Pole. Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. Here are the stars of the Big Dipper, at their various distances from Earth, via AstroPixie . How the Big Dipper’s star are moving in space. Astronomers sometimes speak of the fixed stars, but they know that the stars are not truly fixed. They move in space. Thus the star patterns that we see today will slowly but surely drift apart over the long course of time. But even 25,000 years from now, the Big Dipper pattern will look nearly the same as its does today.

Astronomers have found that the stars of the Big Dipper (excepting the pointer star, Dubhe, and the handle star, Alkaid) belong to an association of stars known as the Ursa Major Moving Cluster. These stars, loosely bound by gravity, drift in the same direction in space. In 100,000 years, this pattern of Big Dipper stars (minus Dubhe and Alkaid) will appear much as it does today! But there will be some differences, as illustrated in the drawing below: Stars of the Big Dipper today – 100,000 years ago – and 100,000 years from now via AstroPixie Bottom line: Watch for the Big and Little Dipper asterisms in the northern sky! A | Define A at Dictionary.com not know from A to B, to know nothing; be ignorant. a [uh; when stressed ey] /ə; when stressed eɪ/ Spell not any particular or certain one of a class or group: a man; a chemical; a house. 2. one at a time; two of a kind; A Miss Johnson called. 3. a Cicero in eloquence; a Jonah. 4.

one (used before plural nouns that are preceded by a quantifier singular in form): a hundred men (compare hundreds of men); a dozen times (compare dozens of times). 5. indefinitely or nonspecifically (used with adjectives expressing number): a great many years; a few stars. 6. one (used before a noun expressing quantity): a yard of ribbon; a score of times. 7. Middle English; orig. preconsonantal phonetic variant of an 1 Usage note Expand In both spoken and written English the choice of a1 or an 1 is determined by the initial sound of the word that follows. Before a consonant sound, a is used; before a vowel sound, an: a book, a rose; an apple, an opera. Problems arise occasionally when the following word begins with a vowel letter but actually starts with a consonant sound, or vice versa. Some words beginning with the vowel letter u and all words beginning with the vowel letters eu are pronounced with a beginning consonant sound, as if the first letter were y: a union; a European. Some other spellings that begin with a vowel letter may also stand for an initial consonant sound: a ewe; a ewer.

The words one and once and all compounds of which they are the first element begin with a w sound: a one-room apartment; a once-famous actor. The names of the consonant letters f, h, l, m, n, r, s, and x are pronounced with a beginning vowel sound. When these letters are used as words or to form words, they are preceded by an: to rent an L-shaped studio; to fly an SST. The names of the vowel letter u and the semivowel letters w and y are pronounced with a beginning consonant sound. When used as words, they are preceded by a: a U-turn; The plumber installed a Y in the line. In some words beginning with the letter h, the h is not pronounced; the words actually begin with a vowel sound: an hour; an honor. When the h is strongly pronounced, as in a stressed syllable at the beginning of a word, it is preceded by a: a history of the Sioux; a hero sandwich. (In former times an was used before strongly pronounced h in a stressed first syllable: an hundred.

) Such adjectives as historic, historical, heroic, and habitual, which begin with an unstressed syllable and often with a silent or weakly pronounced h, are commonly preceded by an, especially in British English. But the use of a rather than an is widespread in both speech and writing: a historical novel; a habitual criminal. Hotel and unique are occasionally preceded by an, but this use is increasingly old-fashioned. Although in some dialects an has yielded to a in all cases, edited writing reflects usage as described above. a2 [uh; when stressed ey] /ə; when stressed eɪ/ Spell ten cents a sheet; three times a day. Origin orig. Middle English a, preconsonantal variant of on (see a- 1); confused with a 1 a3 preposition 1. Pronunciation Spelling. a reduced, unstressed form of of (often written as part of a single, unhyphenated word): cloth a gold; time a day; kinda; sorta. Origin Middle English; unstressed preconsonantal variant of of 1 a4 auxiliary verb, Pronunciation Spelling. 1.

a reduced, unstressed form of auxiliary have, following some modals, as might, should, could, would, and must (usually written as part of a single, unhyphenated word): We shoulda gone. Middle English; phonetic variant of have a5 [uh, a, ah] /ə, æ, ɑ/ Spell British. arterial (used with a road number to designate a major highway): Take the A525 to Ruthin. A the first in order or in a series. 2. (sometimes lowercase) (in some grading systems) a grade or mark, as in school or college, indicating the quality of a student's work as excellent or superior. 3. (sometimes lowercase) (in some school systems) a symbol designating the first semester of a school year. 4. Music. the sixth tone in the scale of C major or the first tone in the relative minor scale, A minor. a string, key, or pipe tuned to this tone. a written or printed note representing this tone. (in the fixed system of solmization) the sixth tone of the scale of C major, called la. the tonality having A as the tonic note. 5. Physiology.

a major blood group, usually enabling a person whose blood is of this type to donate blood to persons of group A or AB and to receive blood from persons of O or A. British. a designation for a motion picture recommended as suitable for adults. Compare AA (def 5), U (def 6), X (def 9). 12. a proportional shoe width size, narrower than B and wider than AA. 13. a proportional brassiere cup size, smaller than B and larger than AA. 14. a quality rating for a corporate or municipal bond, lower than AA and higher than BBB. Å a-1 1.

a reduced form of the Old English preposition on, meaning “on,” “in,” “into,” “to,” “toward,” preserved before a noun in a prepositional phrase, forming a predicate adjective or an adverbial element (afoot; abed; ashore; aside; away), or before an adjective (afar; aloud; alow), as a moribund prefix with a verb (acknowledge), and in archaic and dialectal use before a present participle in -ing (set the bells aringing); and added to a verb stem with the force of a present participle (ablaze; agape; aglow; astride; and originally, awry). Origin Middle English, late Old English; cf. a 2, nowadays a-2 a reduced form of the Old English preposition of: akin; afresh; anew. Origin Middle English; see a 3 a-3 1. an old point-action prefix, not referring to an act as a whole, but only to the beginning or end: She arose (rose up). They abided by their beliefs (remained faithful to the end).

Origin Expand Middle English; Old English a- (unstressed), ǣ-, ā-, ō- (stressed; see abb , woof 1, oakum ), rarely or- (see ordeal ) ≪ Germanic *uz- < unstressed Indo-European *uss- < *ud-s, akin to out ; in some cases confused with a- 4, as in abridge a-4 variant of ab- before p and v: aperient; avert. Origin Expand Middle English < Latin ā-, a- (variant of ab- ab- ); in some words < French a- < Latin ab-, as in abridge a-5 1. variant of ad- , used: (1) before sc, sp, st (ascend) and (2) in words of French derivation (often with the sense of increase, addition): amass. Origin Expand Middle English, in some words < Middle French a- < Latin ad- prefix or ad preposition (see ad- ), as in abut ; in others < Latin a- (variant of ad- ad- ), as in ascend a-6 variant of an- 1.

before a consonant, meaning “not,” “without”: amoral; atonal; achromatic. < Latin annō, ablative of annus a.2 < Latin annō, ablative of annus A.2 a plural ending of nouns borrowed from Greek and Latin: phenomena; criteria; data; errata; genera. -a2 1. a feminine singular ending of nouns borrowed from Latin and Greek, also used in Neo-Latin coinages to Latinize bases of any origin, and as a Latin substitute for the feminine ending - ē of Greek words: anabaena; cinchona; pachysandra. an ending of personal names forming feminines from masculines: Georgia; Roberta. < L feminine -a (see -a 2), as Claudia, feminine of Claudius -a4 a suffix designating the oxide of the chemical element denoted by the stem: alumina; ceria; thoria. probably generalized from the -a of magnesia alpha the first letter of the Greek alphabet (A, α). 2. the vowel sound represented by this letter. 3. (initial capital letter) Astronomy. used to designate the brightest star in a constellation. 5. Chemistry.

one of two or more isomeric compounds. 6. the first in a series of related items: frequently used in chemistry and physics. 7. Chiefly British. a mark or grade corresponding to an A. Compare beta (def 8), gamma (def 9). adjective (of an animal) having the highest rank in a dominance hierarchy: the alpha female of an elephant pack. being the most dominant, powerful, or assertive person in a particular group. Put the files in alpha order. 10. Chemistry. pertaining or linked to the carbon atom closest to a particular group in an organic molecule. Origin < Latin < Greek álpha < Semitic; cf. aleph Bronzino 1. Agnolo (di Cosimo di Mariano) [ah-nyaw-law dee kaw-zee-maw dee mah-ryah-naw] /ˈɑ nyɔ lɔ di ˈkɔ zi mɔ di mɑˈryɑ nɔ/ (Show IPA), 1502–72, Italian painter. Dictionary.com Unabridged British Dictionary definitions for a Expand noun (pl) a's, A's, As 1.

the first letter and first vowel of the modern English alphabet 2. any of several speech sounds represented by this letter, in English as in take, bag, calm, shortage, or cobra 3. Also called alpha. the first in a series, esp the highest grade or mark, as in an examination 4. from A to Z, from start to finish, thoroughly and in detail a1 /ə; stressed or emphatic eɪ/ determiner (indefinite article; used before an initial consonant) 1. used preceding a singular countable noun, if the noun is not previously specified or known: a dog, a terrible disappointment 2. used preceding a proper noun to indicate that a person or thing has some of the qualities of the one named: a Romeo, a Shylock 3. used preceding a noun or determiner of quantity: a cupful, a dozen eggs, a great many, to read a lot 4. used preceding a noun indicating a concrete or abstract thing capable of being divided: half a loaf, a quarter of a minute 5. preceded by once, twice, several times, etc. each or every; per: once a day, fifty pence a pound 6.

a certain; one: to change policy at a stroke, a Mr Jones called 7. Compare an 1 See the 1 a2 an informal or dialect word for have they'd a said if they'd known a3 preposition 1. (usually linked to the preceding noun) an informal form of of sorta sad, a kinda waste a4 are(s) (metric measure of land) 3. 1. (music) a note having a frequency of 440 hertz (A above middle C) or this value multiplied or divided by any power of 2; the sixth note of the scale of C major a key, string, or pipe producing this note the major or minor key having this note as its tonic 2. a human blood type of the ABO group, containing the A antigen 3. (in Britain) a major arterial road: the A3 runs from London to Portsmouth 4. (formerly, in Britain) a film certified for viewing by anyone, but which contains material that some parents may not wish their children to see (as modifier): an A film 5. the number 10 in hexadecimal notation 7. (chem) argon (now superseded by Ar) 9.

(in combination) atomic: an A-bomb, an A-plant 15. (biochem) adenine 17. (logic) a universal affirmative categorical proposition, such as all men are mortal: often symbolized as SaP Compare E , I 2 , O 1 18. a person whose job is in top management, or who holds a senior administrative or professional position (as modifier): an A worker See also occupation groupings abbreviation from Latin a(ffirmo) I affirm Bronzino Il, real name Agnolo di Cosimo. 1503–72, Florentine mannerist painter Å not; without; opposite to: atonal, asocial Word Origin from Greek a-, an- not, without a-2 on; in; towards: afoot, abed, aground, aback 2. (literary or archaic) (used before a present participle) in the act or process of: come a-running, go a-hunting 3. in the condition or state of: afloat, alive, asleep A. the first letter in the Greek alphabet (Α, α), a vowel transliterated as a 2.

(Brit) the highest grade or mark, as in an examination 3. (modifier) involving or relating to helium-4 nuclei: an alpha particle relating to one of two or more allotropes or crystal structures of a solid: alpha iron relating to one of two or more isomeric forms of a chemical compound, esp one in which a group is attached to the carbon atom to which the principal group is attached 4. (modifier) denoting the dominant person or animal in a group: the alpha male Word Origin via Latin from Greek, of Phoenician origin; related to Hebrew āleph, literally: ox Alpha noun 1. (foll by the genitive case of a specified constellation) usually the brightest star in a constellation: Alpha Centauri 2. (communications) a code word for the letter a Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd.

1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012 Word Origin and History for a Expand indefinite article, mid-12c., a variation of Old English an (see an ) in which the -n- began to disappear before consonants, a process mostly complete by mid-14c. The -n- also was retained before words beginning with a sounded -h- until c.1600; it still is retained by many writers before unaccented syllables in h- or (e)u-, but is now no longer normally spoken as such. The -n- also lingered (especially in southern England dialect) before -w- and -y- through 15c. as in twice a day, etc., from Old English an "on," in this case "on each." The sense was extended from time to measure, price, place, etc.

The habit of tacking a onto a gerund (as in a-hunting we will go) died out 18c. alpha n. c.1300, from Latin alpha, from Greek alpha, from Hebrew or Phoenician aleph (see aleph ). The Greeks added -a because Greek words cannot end in most consonants. Sense of "beginning of anything" is from late 14c., often paired with omega (last letter in the Greek alphabet) as "the end." Sense of "first in a sequence" is from 1620s. Alpha male was in use by c.1960 among scientists studying animals; applied to humans in society from c.1992.

a- in native (derived from Old English) words, it most commonly represents Old English an "on" (see a (2)), as in alive, asleep, abroad, afoot, etc., forming adjectives and adverbs from nouns; but it also can be Middle English of, as in anew, abreast (1590s); or a reduced form of Old English past participle prefix ge-, as in aware; or the Old English intensive a-, as in arise, awake, ashame, marking a verb as momentary, a single event. In words from Romanic languages, often it represents Latin ad- "to, at." [I]t naturally happened that all these a- prefixes were at length confusedly lumped together in idea, and the resultant a- looked upon as vaguely intensive, rhetorical, euphonic, or even archaic, and wholly otiose. [OED] prefix meaning "not," from Latin a-, short for ab "away from" (e.g. avert), or its cognate, Greek a-, short for apo "away from, from," both cognate with Sanskrit apa "away from," Gothic af, Old English of (see apo- ).

prefix meaning "not," from Greek a-, an- "not," from PIE root *ne "not" (see un- ). Online Etymology Dictionary, © 2010 Douglas Harper specific absorption coefficient (often italic) systemic arterial blood (used as a subscript) total acidity alveolar gas (used as a subscript) adenine The American Heritage® Abbreviations Dictionary, Third Edition Copyright © 2005 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved. a in the Bible Expand Alpha, the first letter of the Greek alphabet, as Omega is the last. These letters occur in the text of Rev. 1:8,11; 21:6; 22:13, and are represented by "Alpha" and "Omega" respectively (omitted in R.V., 1:11). They mean "the first and last." (Comp. Heb. 12:2; Isa. 41:4; 44:6; Rev.

1:11,17; 2:8.) In the symbols of the early Christian Church these two letters are frequently combined with the cross or with Christ's monogram to denote his divinity. Easton's 1897 Bible Dictionary Constellations: Frequently Asked Questions Constellations: Frequently Asked Questions Throughout the centuries, people have looked to the stars to help them navigate across open oceans or featureless deserts, know when to plant and harvest, and preserve their myths and folklore. Ancient peoples used the appearance or disappearance of certain stars over the course of each year to mark the changing seasons. To make it easier to "read" this celestial calendar, they grouped the brighter stars into readily recognizable shapes, the constellations. Table of the Constellations (or preformated version ) Activity Corner: build Orion How many constellations are there? Astronomers officially recognize 88 constellations covering the entire sky in the northern and southern hemispheres.

Currently, 14 men and women, 9 birds, two insects, 19 land animals, 10 water creatures, two centaurs, one head of hair, a serpent, a dragon, a flying horse, a river and 29 inanimate objects are represented in the night sky (the total comes to more than 88 because some constellations include more than one creature.) It is important to realize that the great majority of star patterns bear little, if any, resemblance to the figures they are supposed to represent and whose name they bear. The ancient constellation-makers probably meant for them to be symbolic, not literal, representations of their favorite animals or fabled heroes, a kind of celestial "Hall of Fame." Who invented them? Our modern constellation system comes to us from the ancient Greeks. The oldest description of the constellations as we know them comes from a poem, called Phaenomena, written about 270 B.C. by the Greek poet Aratus. However, it is clear from the poem that the constellations mentioned originated long before Aratus' time. No one is sure exactly where, when, or by whom they were invented. And yet a little detective work reveals a plausible origin.

The first clue is that Aratus' constellations did not include any near the south celestial pole (the point on the celestial sphere directly above the Earth's south pole) because that area of the sky was always below the horizon of the ancient constellation-makers. From the size of this uncharted area of the sky, we can determine that the people responsible for the original constellations lived near a latitude of 36° north -- south of Greece, north of Egypt, but similar to the latitude of the ancient Babylonians and Sumerians. In addition, the constellation-free zone is not centered exactly on the south celestial pole. Because of a "wobble" of the Earth's axis of rotation, the position of the celestial poles changes slowly with time, a phenomenon known as precession. The uncharted area is centered on the place in the sky where the south celestial pole would have been around the year 2000 B.C. This date matches the time of the Babylonians and Sumerians. Thus it seems likely the Greek constellations originated with the Sumerians and Babylonians.

From there, knowledge of the constellations somehow made its way to Egypt (perhaps through the Minoans on Crete who had contact with the Babylonians and settled in Egypt after an explosive volcanic eruption destroyed their civilization), where early Greek scholars first heard about the constellations and wrote about them. In 150 A.D., the Greek scientist Ptolemy published a book, known by its Arabic name, The Almagest , which contained a summary of Greek astronomical knowledge, including a catalog of 1022 stars, with estimates of their brightness, arranged into 48 constellations. These 48 formed the basis for our modern constellation system. Over the years, astronomers have added constellations to fill in the gaps between Ptolemy's figures and map the uncharted regions of the sky near the south celestial pole. Major contributors of new constellations included Dutch cartographer Gerardus Mercator in 1551 and Pieter Keyser and Frederick de Hautmann, navigators aboard some of the first trading expeditions to the East Indies in the early 1600s, who mapped the southern sky.

Polish astronomer Johannes Hevelius in 1690 and French astronomer Nicolas Louis de Lacaille in the 1750s filled in the remaining gaps in the northern and southern skies. Are there obsolete constellations? Over the centuries, some astronomers have attempted to name constellations after themselves or to flatter a patron or king. This reached a peak during the heyday of celestial mapping in the seventeenth and eighteenth centuries. Few of these survived longer than the astronomers who named them, although they sometimes can be seen in antique star charts. For example, in 1678, Edmond Halley (of Halley's Comet fame) invented a constellation called Robur Carolinum, or Charles' Oak, in honor of King Charles II of England. This constellation did not last long, especially after its rejection by the French astronomer Lacaille in his maps of the southern sky. In 1754, the English naturalist and noted satirist John Hall invented thirteen constellations based on rather unappealing animals such as a toad, a leech, a spider, an earthworm, and a slug.

Fortunately, even though they may have been intended as a joke, they never caught on. At its first meeting in 1922, the International Astronomical Union (IAU), astronomy's governing body which is responsible, among other things, for assigning names to celestial objects and features on those objects, officially adopted the list of 88 constellations that we use today. Definitive boundaries between constellations, which extend out beyond the star figures, were set in 1930, so that every star, nebula, or galaxy, no matter how faint, now lies within the limits of one constellation. For today's astronomer, constellations refer not so much to the patterns of stars, but to precisely defined areas of the sky. Where do individual star names come from? The ancient Greek tradition was to name stars by their position within a constellation. For example, Ptolemy refers to one star by the description "the reddish one on the southern eye," a star we now know as Aldebaran in the constellation of Taurus the Bull. But these descriptions could get quite involved.

Ptolemy refers to another star in the obsolete constellation of Argo the Boat as "the northernmost of two stars close together over the little shield in the poop," a bit cumbersome if you are trying to learn the names of many stars. When Al-Sufi, one of the greatest Arabic astronomers, published his own version of Ptolemy's Almagest in the tenth century, he introduced many individual star names. For centuries, bedouin Arabs had given names to bright stars -- for example Aldebaran and Betelgeuse -- since they regarded single stars as representing people and animals. Many of the original meanings of the names had been forgotten even in Al-Sufi's time, but some were direct translations of Ptolemy's descriptions. For example, the star name Fomalhaut (in the constellation of Pisces) comes from the Arabic for "mouth of the southern fish," which is how Ptolemy described it in the Almagest. After the tenth century, the works of Ptolemy and others were re-introduced into Europe by the Islamic Arabs, and the Greek books were translated from Arabic into Latin, the scientific language of the day.

Thus we know Ptolemy's work from its Arabic translation, The Almagest, not by its original Greek title. And it explains why we have a system of Greek constellations with Latin names containing stars with Arabic names. Did other cultures also see constellations in the sky? Nearly every culture on Earth has seen patterns in the stars. But, not surprisingly, very few have seen the same patterns. Take, for example, the Big Dipper, perhaps the most recognizable star pattern in the sky. The Big Dipper is not actually a constellation itself, but is part of a larger pattern known to the Greeks as Ursa Major, the Great Bear. The seven stars of the Big Dipper have inspired many stories, perhaps because they are bright and located so near the north celestial pole, around which the stars rotate during the course of the night. But not everyone calls it a Dipper. The British call it a Plough. In Southern France, it is a Saucepan. The Skidi Pawnee Indians saw a stretcher on which a sick man was carried. To the ancient Maya, it was a mythological parrot named Seven Macaw. Hindu sky lore called it the Seven Rishis, or Wise Men.

To the early Egyptians, it was the thigh and leg of a bull. The ancient Chinese thought of it as a special chariot for the Emperor of the Heaven or some other celestial bureaucrat. For the Micmac Indians of Canada's Maritime Provinces, along with several other North American Indian tribes, the bowl of the Big Dipper was a bear, and the stars in the handle represented hunters tracking the bear. And in the nineteenth century, the Big Dipper became a symbol of freedom for runaway slaves, who "followed the Drinking Gourd" to the northern states. Are all the stars in a constellation the same distance away from us? No. With few exceptions, the stars in a constellation have no connection with one another. They are actually at very different distances from the sun (see Activity Corner) Chance alignments of stars have created the patterns we see in the sky. Are the constellations permanent? Ancient astronomers often spoke of the "fixed stars," which maintained permanent positions in the sky. And, indeed, the stars do seem almost fixed in place; the patterns they form look much the same today as they did when the constellations were first named nearly 3000 years ago.

But the stars are all moving relative to the Sun, most with speeds of many kilometers per second. Because they are so very far away, it will take thousands of lifetimes to see significant changes in the star patterns. But, over time, they will change. Because of the motions of the stars within it, for example, the handle of the Big Dipper will, in about 50,000 years, appear significantly more bent than it is today (see figure at left). We will, no doubt, keep the same names for the constellations, even if the stars change their positions. Constellations are, after all, products of human imagination, not nature. Other Constellation Activities Given a star chart without constellation figures marked on it (whether real star charts or made-up star patterns), students can invent their own constellations, looking for patterns in the stars that appeal to them. Students can then be asked to make up stories to go with their new constellations. Older students can research the constellation patterns and stories that other cultures saw in the night sky and compare them to the more familiar Greek ones. This can be done by reading books and articles, or by interviewing family members or friends.

Maps of the stars in the constellations can be useful in the classroom. Slide sets, such as Star Maps (a sample of which is on the front page of this newsletter) which show actual pictures of each constellation in the night sky and separate line drawings of the constellation figures, can help students identify the constellations as part of homework assignments or evening "star parties." This can be especially helpful for students without easy access to a planetarium. For Further information about Constellations: Allen, R. Star Names: Their Lore and Meaning. 1899, 1965, Dover Books reprint. Krupp, E. Beyond the Blue Horizon: Myths and Legends of the Sun, Moon, Stars and Planets. 1991, Harper Collins. Proctor, P. Star Myths and Stories. 1972, Exposition Press. Ridpath, I. Star Tales. 1988, Universe Books. Especially for Younger Children: Rey, H. A. Find the Constellations. 1976, Houghton-Mifflin. A classic guide with simplified diagrams and text. Schatz, D. Astronomy Activity Book.

1991, Simon and Schuster. Wonderful book of astronomy activities for the whole family or elementary and middle schools.

Question: What 'C' is used to describe a group of fixed stars?
Answer: Constellation